The proposed synthesis of pseudopterolide addresses several meaningful scientific issues. Pseudopterolide is a natural product with particularly interesting biological activity. It disrupts cell division via a selective mechanism and is cytotoxic at concentrations of 1-10 muo1/M. The highlight of the proposed synthesis is the implementation of an enyne metathesis reaction that should allow the conversion of a cyclophane into the desired strained ring system in one efficient step. One of the goals of the synthesis is to broaden the scope of this metathesis by subjecting new types of substrates to the reaction conditions. This ring-expanding enyne metathesis forms the basis for the assembly of a large ring with several stereocenters, constituting a new synthetic approach to the pseudopterane natural products. Other interesting steps in the proposed route include the diasteroselective macrocyclization of a trichloroallylsilane, an unusual epoxidation sequence, and a stereo- and regioselective coupling reaction proceeding through an apparent pi-allyl nickel complex. Taken together, the chemistry that will be explored over the course of this research will be illuminating, efficient. and most importantly, should result in discoveries that will help to expand the frontiers of synthetic chemistry.